Fuel injectors are integral components of many modern engine systems, and range in application from use in relatively small portable diesel and gasoline engines to very large power generation and marine propulsion systems. The basic function of a conventional fuel injector is to deliver a relatively precise amount of pressurized fuel into a combustion chamber of an engine at a desired timing. The service life of many fuel injectors is relatively long, on the order of at least thousands of hours. This relatively long duty cycle coupled with the relatively severe operating environment and high fluid pressures associated with fuel injection tend to result in wear on various parts of the injector. Over time, the wear experienced by an injector can affect its performance, and under certain circumstances can even render the injector and its associated engine combustion chamber inoperable.
It is common for certain injectors to become internally clogged via relatively viscous petroleum-derived substances. Fuel injector spray orifices may also become at least partially clogged due to carbonized deposits from high temperature combustion products. When an engine system is dismantled for maintenance or rebuild, the injectors are typically removed, their performance evaluated, and the injectors subsequently cleaned and prepared for further service, or at least partially scrapped. Economic losses associated with scrapping fuel injectors and fuel injector parts have long plagued the engine industry.
Another type of fuel injector performance problem which results in scrapping of a large number of fuel injector parts across the industry relates not to clogging and flow restriction, but to the tendency for injector spray orifices to enlarge. Under certain conditions, spray orifices may become enlarged due to fluid erosion of the inner walls of the orifices. This tendency has been shown to be particularly acute with injectors utilizing relatively higher pressures and flow rates, such as are commonly used in certain larger diesel compression ignition engines. In other words, over the course of many hours of operation, fuel sprayed out of the injector spray orifices under high pressure can erode the inner walls of the spray orifices, increasing orifice size and resulting in excess fuel sprayed into the engine cylinder associated with a particular injector.
Certain injectors which have a tendency to eventually develop a high flow condition can weigh well over twenty pounds, and be quite expensive, particularly due to the extensive and fairly precise machining used in their manufacture. Thus, there is a substantial need in the industry for a means to salvage components of these relatively large, heavy duty and expensive injectors, in particular the fuel injector tips. Certain earlier attempts at remanufacturing fuel injectors involved scrapping many of the injectors and/or parts where only the injector tips were out of specification, and attaching new tips to remanufactured injector bodies.
The present disclosure is directed to one or more of the problems or shortcomings set forth above.